IWC Modified Movements Explained

There doesn't seem to be some clear answer to what IWC exactly does when modifying the ETA/Valjoux movements but this article briefly discusses the few things IWC does, more specifically the Valjoux 7750 movement. The article is a bit old, circa 1998, but I believe the method still hold true. It is still a good and very interesting read nonetheless.

The following is a translation from the Uhrenjournal, 20 November 1998, an Austrian watch publication

Question:
How can a fine watch manufacturer such as IWC, state, that despite using an ETA-serial calibre, it renders a base ETA movement into a new, superior IWC movement? For example, what changes are made to an ETA-Valjoux 7750 calibre before it is built into an IWC chronograph?

Many watch manufacturers purchase their calibres from the serial base calibre manufacturer ETA. ETA offers a wide variety serving most needs. However, for many watch collectors seeking limited production calibres, this is just the reason to avoid buying a watch with an ETA movement. What if a renowned manufacturer such as IWC Schaffhausen would use the actually very good and tested ETA Valjoux 7750 for its chronographs, after undertaking numerous modifications? What speaks against the ETA movement? Actually, only the fact that it is widely used and therefore not very exclusive. In turn, what speaks for the ETA movement is that, due to the high production, it is a mature and technically impeccable movement. There are no "infant illnesses" and it is constantly developed further. Why therefore should IWC overlook the best serial chronograph-movement? Obviously, there are other alternatives, however, from an economic and technical standpoint, the decision for the Valjoux is guaranteed to be the right move.

Now, what does IWC do with this calibre, and why do they treat it as if it were their own movement? The explanation is pretty simple: IWC purchases the best serial engine and undertakes on that basis the best possible engine tuning. You could say that IWC does what AMG does with Mercedes engines, Alpina with BMW or Abt with VW or Audi engines. Serial engines are used, which in turn are tuned and optimized with the best experience available.

In the case of the Valjoux, the calibre is only bought in its components, never readily assembled. In addition, only the best possible version is purchased - the so-called Chronometer version. When the components arrive in Schaffhausen (IWC's factory location) there are first of all checked by eye, and then randomly checked in detail. Some components of the original ETA calibre are immediately eliminated and are never used by IWC. They are replaced by usually more expensive and better ones.

The entire escapement is a good example. It is ordered separately with different, more exact technical IWC specifications and is only fitted into the calibre at the end of the assembly. Some changes take place even earlier: For instance, all metal bearings of the Valjoux 7760 are replaced by jewel bearings - the Valjoux 7760 (same as the 7750 but in the handwound version) is the basis for the Portugieser Chronograph movements. There is an IWC expert whose job it is to extract by hand all metal bearings from the supplied calibre and replace them with the more expensive jeweled bearings. This is an effort, which will ultimately significantly increase the longevity of the movement.

This exercise is futile in the version 7750 as it only comes with jewels. Instead numerous cogwheels are replaced. For instance, one is part of the winding mechanism, which ETA supplies with three holes in order that it can be worked on by machines and be transported by robot arms. As the holes are drilled, there is some metal, which is pushed over the surface - causing friction with the above-located bridge. Now IWC found out that it is precisely the position of these holes, which will cause fine metallic debris over time to accumulate. In the short run, such metallic debris is not a problem, however over a longer period such debris will cause problems.

Many more examples could be listed at this point, reaching far beyond the space allocated for this article. Therefore, let's come back to the escapement of the movement. Before the escapement is fitted into the movement, a specially trained, female horological expert (so-called regleuse) checks each hairspring for unevenness. How does she do it? Quite simple, she holds the escapement with a special device and turns it. Then she makes sure with her magnifying glass than the escapement unfolds in concentric circles. If not, she manually bends the hairspring to perfection. Again, this in an effort of which the value is only apparent in the sum of all efforts and is ultimately reflected in the accuracy of the movement. The pinnacle of all these tuning efforts lies in completely replacing the barrel. There are some many changes and modifications to the calibre 7750 leading to far lower power requirements of the movement. As a result the original ETA barrel is now far too strong for the modified IWC movement. A "weaker" IWC barrel brings about significant advantages. All moving parts suffer far less wear and tear because there are exposed to far smaller forces - again, this significantly prolongs the average life of an IWC movement.

It is not exaggerated if IWC makes the statement that it treats the ETA movements as if it were an original IWC movement. The numerous modifications and the great care, completely transform the original, mass-produced movement by ETA into another movement. ETA is not necessarily ETA as it is often falsely stated.

Re: IWC Modified Movements Explained

Originally Posted by Time Flies on September 20, 1998
Copyright, 1998, 1999, G. J. Buhyoff

Well, I can see that it is time to post this. l wanted to wait until I had even more information about the sealing process used in the IWC Aquatimer and some additional detail about movement parts finishing...but, there seems to be enough argument and misguided thought expressed on the Forum to hasten this post.

First, Aquatimer uses an IWC cal. 32524 movement which is "based" upon an ETA 2892. It is NOT an ETA 2892 in the same way that the Valjoux 7750 in the Flieger Chrono is not a Valjoux 7750. Both IWC movements are BASED upon these two more commonly used movements. l don't want to restate what I and others have said over and over and over again. So, I will reference some important REQUIRED reading at the end of the piece.

Before, I itemize what I have discovered from my sources regarding the Aquatimer's Cal. 32524, let me note a few related thoughts. First, what movement should IWC have used in the Aquatimer? A JLC 889 base? I do not believe this would have been a good choice. The 889 is a bit too delicate and sensitive to losing adjustment without special external (to the movement) shock absorption (ala the Inegeniuer). The Aquatimer is designed to be tough sport watch that is intended to take a beating commensurate with its 2000 meter water resistance rating and its 3.2mm thick sapphire crystal.

So, what would you use? A tough reliable handwound movement? Yes, that might have been a good choice but the market is looking for automatic movements in all liklihood and a sport watch, especially one engineered for diving, likely demands an automatic movement. What other JLC movement would qualify for a sport watch? Think about it. What movement design, short of designing a new movement, fits the bill? Design a new movement? Boy, that would sure limit the sales of the Aquatimer since the price would be much higher due to the consumer having to absorb the cost of R&D and retooling.

The 2892 is used in wide range of watches and what does matter is that the design of the movement, while not particularly elegant to some, is a workhorse that has been around for a long while and improved over time (see reading below authored by Walt Odets). More importantis what HAS BEEN DONE to the stock movement, not the movement base or kit.

Secondly, l would like to quote my friend Michael Freidberg in a post he made -

"When I met with Renee Schwartz, head of service for IWC Schaffhausen, at the Basel Fair, l specifically raised with him thesubject ofIWC using ETA 2892 ebauches. He explained that IWC replaces most of the critical parts with parts of their own specification, including replacing the wheels with a stronger metal composition, and also the use of a longer mainspring for theoretically greater accuracy. When I met with IWC in Schaffhausen, l learned that IWC finishes its movements to its higher specifications and assembles all base movements from scratch -- even when they use JLC ebauches. A 2892 is really a design -- and there is nothing wrong with the design. If it is implemented with high quality parts, finished meticulously and assembled with painstaking care, it can be a very good movement."

Now, here is what I have found about the IWC 32524:

IWC uses a 2892 KIT -- not an assembled ebauche. They take this kit and replace parts or use parts of their own design to meet their own specifications for tolerance and strength. These include:

-the gear train
-wheels and levers
-mainspring and barrel
-a 21 K gold mass is added to the rotor for winding efficiency
-all parts are finished and assembled by hand

Is this a stock 2892? No. ls it based upon the design of the 2892? Yes. ls it likely to be a fine movement, given the finishing and the parts specifications used ( metalurgy and tolerances) used by IWC? Yes, definitely. Was it a smart choice for IWC? I think so, definitely. IWC has based their caliber on a tough, proven design but likely made it tougher and one with greater expected longevity due to the application of their specification standards, finishing and hand assembly.

Finally, I am always a little amazed that some people do not use the fantastic resources that are available via TimeZone including Jack Freedman's Escape Wheeling series, Walt Odet's Horologium pieces and the array of other archived posts as well as the posts on the Bulletin Board.

I strongly suggest you read the following related posts that will give further detail about the subjects I have spoken about in the post above. My research and the citations below ought to answer many of the questions you might have about why the IWC caliber 32524 is not really an ETA 2892, but rather a caliber BASED upon the ETA 2892. In addition, be sure to read Mycroft's post about IWC Titanium finish and information regarding the sealing system used in the Aquatimer.

Re: IWC Modified Movements Explained

As much as I would love to see IWC go to an all in-house movement company, I would hate that it won't be affordable to most. I mean their cheapest in-house movements starts at what, $5,600 with the Calibre 80110 on the AMG Ingy? I guess it's not bad but I do not want to see IWC watches starting at that price, it would get rid of too many beautiful watches in their line-up, ie: Pilot, Spitfire, almost all chrono watches, etc...

Since I mentioned the 80110 movement, here's a quick article on the subject:

IWC´s new flagship is introduced in three basic references: a regular model (reference IW3227), a mid-size model (reference IW4515) and, for the first time in the Ingenieur line, a mechanical chronograph (reference IW3725). The line-up is completed by two "Edition AMG" variants with Titanium cases.

To each his own - as we will see, all of them are special.

Starting with the regular model, on first view the Ingenieur Automatic is a very modern approach.
It is a large watch representing design elements known from the reference 1832 "Jumbo" model, such as an integrated bracelet, a large bezel featuring the typical five holes and a clear legible dial. Thus it is easily identified both as an IWC Ingenieur and bearer of a real heritage, while being new and innovative at the same time. This combination is not easily achieved by every recent successor of a well known model and while the Ingenieur clearly is not a watch for everyone, personally i regard it a very successfull bridge between tradition and innvation. Therefore odds are good the design will seduce not only followers of the post-1976 Ingenieurs, particularly as large watches, such as the "Portugieser" range, are nothing new in the portfolio of IWC.

The dimensions of 42.5 mm in diameter and 14.5mm in height certainly cater the current preference for larger cases and a decidedly masculine look.
But the Ingenieur is not intentionally large only; the external qualities do speak for themselves, including a solid three-part stainless steel case with integrated IWC metal bracelet, both screw-down back and crown and a sapphire glass bearing antireflective coating on both sides.

It would not be a true IWC watch if it were not well in line with IWC´s philosophy and traditions in the field of sports watches.

And thus it is no surprise to learn the large case of course offers hidden values justifying the size, even when considering the "heart" of the new Ingenieur measures 30mm in diameter only.

The new Ingenieur Automatic offers traditional key features of the Ingenieur range; first of all it is highly protected against magnetic fields, which are apt to influence the proper function and accuracy of the movement.

This antimagnetic shielding is achieved by use of a soft-iron inner case, which is typical for Ingenieur models of past 50 years. Like early models of the Ingenieur range, the antimagnetic protection of the new Ingenieur Automatic does include the dial and thus forms a "Faraday cage", which guarantees protection against magnetic fields of up to 80,000 A/m (amperes per metre). This result considerably surpasses the required Swiss standards for antimagnetic watches of 4800 A/m.

In addition, the case and crystal is water-resistant up to 120m depth and, much like the famous MK XI model, low pressure (which can cause displacement of the crystal in case of a drop in air pressure).
Therefore it can and should be noted the casework of the Ingenieur is unusually elaborate and almost understated, with many of the features hidden behind the solid back. It is a piece of classic Schaffhausen craftmanship and engineering. And it is a substantial piece: the weight of the new Ingenieur Automatic including the bracelet of 216 gramms does not make this a light watch.
Nonetheless, the true value is the new movement caliber 80110, representing a first for IWC and the watchmaking world in several aspects.

Inner values: IWC manufacture caliber 80110

The highlight of IWC´s new flagship certainly is the new manufacture made caliber 80110 automatic movement.

The new caliber 80110 does represent a major achievement for the Schaffhausen brand in many aspects. Historically, it is the first newly developed manufacture movement with less than 37mm diameter since four decades ago. And it is the latest family member in a line of movements which made IWC famous, with it´s brethren, such as the famous caliber 8541, frequently referred to as some of the technically best movements ever made.

As we will see, the new caliber 80110 does follow this tradition; but rather than being a retro-design, it offers some new and surprising solutions including the use of new materials.

On first view, IWC´s latest addition seems to be surprising similar to previous movements. This visual relation is probably not uncalled for; according to the details known so far, it is designed to be a sturdy, reliable, effective, service-friendly and long-term accurate micro-machine.
In this the new caliber 80110 follows the same principles as earlier creations by the Schaffhausen brand, which may be regarded corner stones of the brand´s fame.

The new caliber 80110 again makes use of Albert Pellaton´s ingenious invention, the famous winding system with rockers and pawls that is know from earlier movements by IWC, but recent additions like the 5000 caliber family as well. The Pellaton winding is widely regarded as a most effective and reliable bi-directional winding system; 50 years of use do speak for themselve in this regard.

As we see, a key issue during development was shock protection and as we will see later, it is achieved by unique solutions. IWC claims the result to be the "definite improvement of the integrated shock-absorbing system" and the new caliber 80110 automatic movement to come with "the most effective protection against jolts and jarring".

Another familiar feature is the special shock protection by means of a flexible rotor bridge; the rotor bearing rests on a "S-shape" bridge which allows bending in case of lateral and horizontal shocks. This is achieved by mounting the rotor bridge with two attachment points only; this way, the S-shaped "arm" positioned on the opposite perimeter remains flexible. Again, this is a construction known from early IWC automatic movements and it´s proven to work exceptionally well.

But the visual similarity ends on closer view.
The first major difference is, much like the case, the size of the movement. A comparison may clearify:
IWC last manufactory-made automatic caliber 8541 was measuring 12.5 ligne (28mm) in diameter and 5.9mm in height; the new caliber 80110 does exceed these dimensions, measuring 30mm in width and 7.20m in height.

And again, the additional space does not remain unused.
Apparently all parts are significantly thicker than their predecessors; an aspect usually indicating a more sturdy construction. But it would not be IWC to increase the mass only, without caring for the details; an example is the re-designed rotor, which now is crafted with cut-out sections that increase flexibility in case of severe horizontal shocks.

In this regard, a magic formula is Delrin®.
DuPont Delrin® acetal polyoxymethylene (POM) resins are highly versatile engineering polymers that bridge the gap between metals and ordinary plastics; a sturdy yet flexible material known of applications such as break pads for inline skates.

IWC went out of the box and placed "bumper pads" underneath the rotor; this way, the flexible rotor weight may touch the movement plate and bridges in case of extremely severe impacts on the watch case, but due to the use of the Delrin pads no harm can happen to the plates themselves.

It is an application much in the spirit of IWC; seemingly simple and most effective. It is the first application of this kind in any watch movement and promising to work extremely well; a material sturdy enough to be used as a break pad is likely to withstand the forces in a watch movement even more easily, while being flexible enough not to scratch any other parts. From my perspective this makes a perfect addition to the especially shock-protected layout of caliber 80110 and to my understanding it is an inventions that really makes a lot of sense, with some real value added for any future customer.

The only downside - hardly any owner will be able to see the new pads, as they remain invisible in the assembled movement.